You know it’s true. How many times have you seen teens and young adults staring at their phones while they’re “watching” TV?

For that matter, “viewers” at the upper end of the 18-49 and 25-54 demographics do it, too. A report by eMarketer estimated that in 2017, 177.7 million adults regularly (at least monthly) used a second-screen device — smartphone, tablet, laptop — while they “watched” TV. That’s projected to increase to 185.8 million this year, and 193.5 million in 2019.

Steve Levitan, a nine-time Emmy winner who co-created and executive produces “Modern Family” (Wednesdays, 8 p.m., ABC/Ch. 4), is aware of the problem, but sort of throws up his hands. He said it doesn’t affect the way the show is written or produced.

(Photo courtesy of Tony Rivetti/ABC) Creator/executive producer Steve Levitan (second from right) on the set of “Modern Family.”

“What can you do? We’re always trying to just make the most compelling television possible,” he said. “So if you said, ‘OK, now your goal is to try to keep people watching without looking at their phones,’ well, what would you do? Would you maybe try harder? Write harder?”

It’s definitely frustrating for people in the entertainment industry. That includes “Superior Donuts” (Mondays, 8 p.m., CBS/Ch. 2) star/writer/executive producer Jermaine Fowler, who admits he uses his phone to check notes when he’s performing stand-up comedy.

“But you’d think somebody could watch a show for half an hour without getting on their phone,” said Fowler, who’s taking a break from social media in part because he’s tired of seeing tweets from people who criticize shows they’re only half-watching.

“Social media and technology have sort taken away people’s attention,” he said. “They do form an opinion, but sometimes … it’s just coming from a place of not trying to understand why they feel that way. Give it your attention first. And then I’ll listen to you.”

“Viewers” who never look up from their phones are “hugely” affecting the TV industry, according to Rob Wade, Fox’s president of alternative entertainment and specials.

“I say this to my showrunners — it’s not just about what you’re putting on the screen. You don’t need to just think about the iceberg above the water, you need to think about the huge tower below. … That’s always on our mind now.”

(Photo courtesy of Evans Vestal Ward/NBCUniversal) Jennifer Salke is the president of NBC Entertainment.

“It’s something we think about a lot,” she said. “The question is — what can we do?”

And that is “a very good question,” according to Zach Braff (“Scrubs”). “And you really can’t do much.”

That doesn’t keep him from trying. Braff and Matt Tarses are the executive producers of “Alex, Inc.” (Wednesdays, 7:30 p.m., ABC/Ch. 4), a new comedy Braff also stars in. And Braff said he often jokes with Tarses about “drop-the-Dorito moments” in scripts — plot points they need to “hammer home so it’s a little clearer for the person who was reaching for a dropped chip.”

“But, really, it’s for the person who’s looking at their phone,” Braff said. “It’s for the people who are half-watching.”

On the other hand, Elizabeth Meriwether — the creator/executive producer/writer of “New Girl” (Tuesdays, 8:30 p.m., Fox/Ch. 13) — said this never enters her mind “because I treat every episode like every second is important to watch.”

She’s not naïve. She recognizes that not everyone sits down and is glued to the TV for every second of “New Girl.”

“People walk out of the room, come back, they’re cooking dinner,” Meriwether said. Which doesn’t really work with a show like “New Girl,” which has “a million jokes a second and we’re popping back and forth in time.”

“Hopefully, they’ll go back and check on stuff that maybe they missed,” Meriweather said. “It’s the kind of thing where you have to really watch it.”

The producers of “The Good Doctor,” which will return for its second season in the fall, took a somewhat similar approach — they make what’s on the screen so complicated that viewers have to pay attention. Maybe even pause their DVRs and stare intently at their TVs.

The show revolves around a young surgeon, Shaun Murphy (Freddie Highmore), who has autism. And in every episode, there are on-screen graphics meant to illustrate how he thinks and perceives things differently.

(Photo courtesy of Jeff Weddell/ABC) Executive producer Daniel Dae Kim on the set of “The Good Doctor.”

Executive producer Daniel Dae Kim said it’s an attempt to get people to look up from their phones.

“It’s why we incorporated Shaun-vision into the show,” said the former “Lost” and “Hawaii Five-0” star. “If we show a graphic that there’s no way anybody can read in real time, we understand that people can stop, look at it, learn a little something and move forward.

“We have to account for the way that people consume media these days.”

This is by no means a new idea. For years, networks have been using second screens to try to engage viewers as episodes are airing. Stars go on Twitter and live chat episodes. Shows produce online-only material to supplement what’s on TV.

Meriwether said she thinks “fan involvement on Twitter” can help a show. Levitan is less convinced.

“I think people will find a way to have a second screen and still have their Instagram feed,” he said.

(Photo courtesy of Frank Micelotta/Fox/PictureGroup) Rob Wade is Fox's president of alternative entertainment and specials.

And Wade said that live-chats are already old news — just marketing tools to get people to watch shows as they exist today.

“The other side of it is, actually, how do we use these things to make better shows?” Wade said.

“Shaun-vision” on “The Good Doctor” is one attempt. This summer, we’ll see a revamped version of the musical game show “Beat Shazam” when it rejoins the Fox schedule on Tuesday, May 29. You’ll be able to play along on your phone — and win money.

“I’m really excited to see how that does,” Wade said. “It’s like — how do we use the phone to improve the experience on the screen, not just as a marketing tool? Whether it’s the social media part of it or game play, whatever you can do to reach all parts of the media, to reach all platforms — it’s really important.

“And I think, yes, there will be ways to monetize it.”

The standard answer right now is to make a show so good that viewers will be riveted to the TV screen, not their phones.

“I think most people who watch ‘Game of Thrones’ aren’t looking at their phones,” Salke said. “We need to do that sort of thing, too.”

As has been the case since television began, there’s pressure to make that happen with big events, stunt casting and plot twists that are promoted before they happen. But Levitan believes that attempts to “dial it up” could hurt shows.

“Then you’re thinking about your audience rather than thinking about the story and the characters and what you want to do,” Levitan said. “You’ve got to still write it assuming people are going to sit and watch it.

“And if they choose to look elsewhere, hopefully they’re doing it with your show on.”